Print developing machine and apron therefor



Sept. 12, 1950 T c. HARPER PRINT DEVELOPING MACHINE AND APRON THEREFOR Filed Jan. 2, 194a Patented Sept. 12, 1950 PRINT DEVELOPING MACHINE AND APRON THEREFOR Thomas 0. Harper, Akron, Ohio, assignor to The B. F. Goodrich Company, New York, N; Y., a corporation of New York Application January 2, 1 s, Serial'N'o, 294

i 1 I yThis inventionrela'tes to the dry development of photographic prints and is especialiy'useful in "the dry development of prints by -ammonia or other gases.

hi the development of photographic prints of drawings, ammoniafumes are generated-within a container having a perforate top, and the prints are: progressively passed over the container by an endless apron. Heretofore difficulties have been experienced in that such aprons as have been employed have become smooth and glazed in use and have: interfered with properfeeding of the prints. Furthermore, suchaprons at times have not" permitted good circulation of the fumes about the print, resulting in reduction'o'f speed of-the machine, while, at the same time fumes have been permitted to escape undesirablyinto the surrounding atmosphere.

It is an object of the present invention'to overcome the foregoing and other 'diirmulties.

Other objects of the invention are to provide good gripping of the prints for positive feeding, to provide for minimizing the escape of the fumes especially in the direction of apron travel, to provide a, straightqunning flexible apron, and fur ther to provide high flexibility of the apron.

These and other objects will appear from the following description and the accompanying drawings.

Of the drawings, 7

Fig. 1 is a cross sectional view of a print-developi'ng machine showing the fuming container, the apron, and the supportin rollers therefor, other'parts being broken away.

Fig. 2 is aperspective view of a, portion of the apron.

Referring to the drawings, the numeral Hides 'i gnates a closed container defining a fume chamher and having a convexly curved upper wall I i having perforations it. at regular intervals thereover for emitting fumes. Ammonia water is heated within the container to provide ammonia gas therein. The prints, such as M, are gripped and fed across the convex perforate face of the container i ll progressively by an apron l5 trained about guiding and driving rollers I6, I! with the lower reach of the apron opposed to the convex surface of the container, tension being applied to the apron by a tension guide roller !8.

The apron i5 is formed of a stretch-resisting body 20 of rubberized fabric having a protective back layer 2! of rubber or other rubber-like material and a face layer 22 also of similar rubberlike material vulcanized to each other.

To provide positive feed of the prints and at.

8 Claims. (C1. 95-89) thesame time to permit good circulation of fumes through and about the printswhile confinin the fumes from undesirable escape in the direction of apron travel, the face layer 22' is formed of alternate, laterally extending ribs 24' and grooves 25, the lateral-1 y extending ribs being rounded to seal off the fumes-under light tensioning of the apron alon parallel lines extending perpendicular to the direction of traveler the apron. As'the apron is wider than its reach in contact with the con tainer, this construction substantially seal-s in'the fumes permitting escape only at the sides of the apron Where the fumes may be readily carried away byeXh-aust tans, such slight escape being beneficial in permitting how of fumes laterally good grip upon the paper of the prints while at the same time sealing oif'the fumes.

Variations may be made without departing from the scope of the invention as it is defined by the following claims.

' I claim:

1. In apparatus for the dry development of photographic prints, the combination of a fume chamber having a print-contacting surface, and

an apron movable over said surface in contact vwith a print thereon, said apron comprising a body of flexible material having a print-contacting face of resilient rubber-like material with a succession of fume-conducting grooves in said face disposed cross-wise of said .face and perforated surface for circulation of fumes reaching said grooves from the perforations of said surface, said face of the apron having print-contacting and chamber-contacting portions between and coextensive with said grooves cross-wise of the apron to restrict travel of fumes longitudinally of the apron and frictionally engage a print for advancing it over said surface.

2. In apparatus for the dry development of photographic prints, the combination of a fume chamber having a perforated print-contacting surface, and a flexible apron movable along said surface with a face of the apron toward said surface, said face comprising a series of grooves disposed cross-wise of the apron and, alternating with said grooves, a series of ribs of resilient rubber-like material coextensive with said grooves cross-wise of the apron and presenting longitudinally spaced-apart surfaces engageable with a print at spaced-apart positions along the same for advancing the print along said surface and for restricting flow of the fumes in the longitudinal direction of the apron.

3. In apparatus for the dry development ofv photographic prints, the combination of a fume chamber having a perforated print-contacting surface, and an apron movable along said surface with a face of the apron toward said surface, said apron comprising a body of flexible material hav-"' ing a. print-contacting face of resilient rubberlike material with a succession of fume-conducting grooves in its print-contacting face disposed cross-wise of said face coextensively with the width of the perforated area of said surface for circulation of fumes reaching said grooves from said perforated surface, said face of said apron having cross-wise ribs alternating with said grooves and presenting relatively narrow portions of said resilient material for contacting a print at-spaced-apart positions along the sam toadvance the print over said surface.

4. In apparatus for the dry development of photographic prints, the combination of a fume chamber having a convex perforated surface for contacting the face of a print, and an apron of greater width than the perforated area of said surface and having a reach movable along said convex surface for advancing a print along said surface between said apron and said surface, said apron comprising an endless body of resilient rubber-like material having a print-contacting face of said rubber-like material with a succession of fume-conducting grooves in said face disposed cross-wise of said face and said perforated area for circulation of fumes reaching said grooves from said perforated surface, said face of the apron having print-contacting and chamber-contacting portions between and coextensive with said grooves cross-wise of the apron to resist travel of fumes longitudinally of the apron and frictionally engage a print for advancing it over said convex surface.

5. A print-developing apron for advancing a.

print along the perforated surface of a fume chamber, said apron comprising a flexible body for advancing along said surface witha' face of the body toward said-surface, said face comprising a series of grooves disposed cross-wise of the apron and, in alternation therewith, a seriesbf print-contacting portions of flexible material spaced-apart longitudinally of the apron towengage a print frictionally at spaced-apart positions along the same for advancing it along said surface. 1

6. A print-developing apron for advancinga .print along the perforated surface of a fume 4 I chamber, said apron comprising a flexible body for advancing along said surface with a face of the body toward said surface, said face comprising a series of fume-conducting grooves disposed cross-wise of the apron for circulation of fumes reaching said grooves from said perforated surface, and said face of the apron having printcontacting and chamber-contacting ribs of resilient rubber-like material between and coextensive with said grooves cross-wise of the apron to resist travel of the fumes longitudinally of the apron and frictionally engage a print at spacedapart positions along the same for advancing it along said surface.

7. A print-developing apron for advancing a print along the perforated surface of a fume chamber, said apron comprising a flexible body foradvancing along said surface with a face of the body toward said surface, said face comprising a series of alternating grooves and ribs disposed cross-wise of the apron, said ribs having longitudinally spaced-apart relatively narrow face portions of resilient rubber-like material engageable with a print on said surface at spacedapart positions along the print to advance it frictionally along the surface.

8. A print-developing apron for advancing a print along the perforated surface of a fume chamber, said apron comprising a flexible endless body of resilient rubber-like material including a flexible reinforcing material therein for advancing along said surface with a face of the said rubber-like material toward said surface, said face comprising a series of fume-conducting grooves disposed cross-wise of the apron for circulation of fumes reaching said grooves from said perforated surface, and said face of the apron having print-contacting and chamber-contacting portions of said rubber-like material between-and coextensive with said grooves cross-wise of" the apron to resist travel of the fumes longitudinally of the apron and. frictionally engage a print at spaced-apart positions along the same for advancing it over said surface.

THOMAS C. HARPER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS France Apr. 19, 1932 

